Compressibility and Collapsibility Characteristics of Sedimented Fly Ash Beds
Publication: Journal of Materials in Civil Engineering
Volume 20, Issue 6
Abstract
The fly ash produced from thermal power plants (TPP) is disposed of in the form of slurry into ash ponds, lagoons, or dykes. Fly ash slurry, after undergoing sedimentation and consolidation processes under its own self-weight, exhibits a different engineering behavior than those compacted after dewatering. Literature review indicated no studies are available on the engineering behavior of sedimented fly ash beds/deposits, which is impeding the recycling efforts of the sedimented fly ash beds/deposits. This paper presents test results from laboratory studies conducted on sedimented fly ash deposits prepared by simulating both natural sedimentation and consolidation processes in a prototype environment. A series of compressibility, consolidation and collapse tests were then conducted on specimens collected from the sediment deposits. Test results revealed that the sedimented fly ash material exhibits a pseudoover consolidation effect including a moderate collapsible behavior and an increased compressibility at applied stresses. Collapse potential of the materials ranged between 0.5 and 1%, indicating a metastable fabric of these materials formed in the sedimentation process. Potential engineering behavioral issues related to recycling efforts of fly ash beds are mentioned.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
This study was supported by the Central Building Research Institute (CBRI), Roorkee, India. The writers, would like to acknowledge this support. Also, they would like to acknowledge Panki Power Plant for providing material support.
References
Ballisager, C. C., and Sorensen, J. L. (1981). “Fly ash as fill material.” Proc., 10th Int. Conf. on Soil Mechanics and Foundation Engineering, Vol. 2, 297–301.
Barton, M. E. (1993). “Cohesive sands: The natural transition from sands to sandstones.” Proc., Int. Symp.—Geotechnical Engineering of Hard Soils-Soft Rocks, 367–374.
Bureau of Indian Standards. (1986). “IS 2720. Part XV: Methods of test for soils: Determination of consolidation properties.” Compendium of Indian Standards on Soil Engineering.
Capco. (1990). “Pulverized fuel ash as a reclamation fill.” Rep., China Light and Power Co. Ltd., Hong Kong, 1–34.
Clemence, S. P., and Finbarr, A. O. (1981). “Design consideration for collapsible soils.” J. Geotech. Engrg. Div., 107(3), 305–317.
Das, S. K. (1992). “Morphological, chemical and mineralogical characterization of some Indian fly ashes.” MTech thesis, Indian Institute of Technology, Kanpur, India.
Das, S. K., and Yudbhir. (2005). “Geotechnical characterization of some Indian fly ashes.” J. Mater. Civ. Eng., 17(5), 544–552.
Gandhi, S. R. (2000). “Densification of deposited ash slurry.” Management of ash ponds for human settlements, Narosa, New Delhi, India, 94–106.
Gandhi, S. R., Dey, A. K., and Selvam, S. (1999). “Densification of pond ash by blasting.” J. Geotech. Geoenviron. Eng., 125(10), 889–899.
Ghosh, A., and Bhatnagar, J. M. (1999). “Reclamation of abandoned fly ash ponds for human settlements: A case study.” Fly ash disposal and deposition beyond 2000 A.D., Narosa Publishing House, New Delhi, India, 162–172.
Ghosh, A., Singh, A., Dinesh, Kumar, D., Misra, S. K., Bhatnagar, J. M., and Singh, J. (1997). “Geotechnical investigations on abandoned fly ash pond for human settlements.” Indian Geotechnical Conf., Vadodara, 379–378.
Gray, D. H., and Lin, Y. K. (1972). “Engineering properties of compacted fly ash.” J. Soil Mech. and Found. Div., 98(4), 361–380.
Havukainen, J. (1983). “The utilization of compacted coal ash in earth works.” Proc., 8th European Conf. on Soil Mechanics and Foundation Engineering, Vol. 2, 773–776.
Horiuchi, S., Kawaguchi, M., and Yasuhara, K. (2000). “Effective use of fly ash slurry as fill material.” J. Hazard. Mater., 76(3), 301–337.
Jennings, J. E., and Knight, K. (1975). “A guide to construction on or with materials exhibiting additional settlement due to collapse of grain structure.” 6th Regional Conf. for Africa on Soil Mechanics and Foundation Engineering, 99–105.
Kaniraj, S. R., and Havanagi, V. G. (1999). “Geotechnical characteristics of fly ash-soil mixtures.” Journal of South East Asian Geotechnical Society, 30(2), 129–147.
Kolay, P. K. (2000). “Characterization, water-interaction and zeolitization of a lagoon ash.” Ph.D. thesis, Indian Institute of Technology, Bombay, India.
Leonards, G. A., and Bailey, M. B. (1982). “Pulverized coal ash as structural fill.” J. Geotech. Engrg. Div., 108(4), 517–531.
Madhav, M. R., and Ghosh, A. (1999). “Reclamation of fly ash beds with granular piles.” Fly ash disposal and deposition beyond 2000 A.D., Narosa, New Delhi, India, 122–129.
Madhav, M. R., and Raja Sekhar, M., Puppala, A. J., and Ghosh, A. (2006). “Reclamation of sedimented and consolidated fly ash deposits.” Proc., Int. Conf. on Environmental Geotechnics, 205–212.
Martin, J. P., Collins, R. A., Browning, J. S., and Biehl, F. J. (1990). “Properties and use of fly ashes for embankments.” J. Energy Eng., 116(2), 71–86.
McLaren, R. J., and Digioia, A. M., Jr. (1987). “The typical engineering properties of fly ash.” Proc., Geotechnical Practice for Waste Disposal, ’87, Geotechnical Special Publication, No. 13, ASCE, New York, 683–697.
Mitchell, J. K., and Soga, K. (2005). Fundamentals of soil behavior, Wiley, Hoboken, N.J.
Porbaha, A., Pradhan, T. B. S., and Kishida, T. (2001). “Static response of fly ash columnar improved ground.” Can. Geotech. J., 38(2), 276–286.
Raza, S. A., Khan, M. A., Ahmad, M. S., and Kumar, S. (2000). “Consolidation behavior of treated and reinforced fly ash.” Fly ash disposal and deposition: Beyond 2000 A.D., Narosa, New Delhi, India, 216–222.
Singh, D. N. (1989). “Engineering properties of compacted Panki fly ash.” MTech thesis Indian Institute of Technology, Kanpur, India.
Sinha, U. N., Karthigeyan, S., Bhargava, S. N., and Sharma, A. K. (1998). “Compressibility characteristics of pond ash used as geomaterial.” Indian Geotechnical Journal, 28(4), 377–387.
Skarzyska, K. M., Rainbow, A. K. M., and Zawisza, E. (1989). “Characteristic of ash in storage ponds.” Proc. 12th Int. Conf. on Soil Mechanics and Foundation Engineering, Rio de Janerio, Vol. 3, 1915–1918.
Sridharan, A., Pandian, N. S., and Rajasekhar, C. (1996). “Geotechnical characterization of pond ash.” Ash ponds and ash disposal systems, Narosa, New Delhi, India, 97–110.
Yudhbir, and Honjo, Y. (1991). “Applications of geotechnical engineering to environmental control.” Proc., 9th Asian Regional Conf. on Soil Mechanics and Foundation Engineering, Vol. 2, Bangkok, Thailand, 431–469.
Information & Authors
Information
Published In
Copyright
© 2008 ASCE.
History
Received: May 18, 2006
Accepted: Nov 28, 2007
Published online: Jun 1, 2008
Published in print: Jun 2008
Notes
Note. Associate Editor: Jason Weiss
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.